I honestly would like one of my players to answer this rather than me, but they only sometimes check in on these boards, and usually just to seek some bit of information here or there.

I DM, and we use several homebrew rules that me and 2 other DMs need to approve before we make it standard. Usually we try not to rule lawyer, and whenever rule lawyering comes up the DM's word is final. (Yes that usually means mine)

We usually play around in T2-3 but we allow any race/class combo with the general consensus of: "If you break the game, the DM will break it just as hard." basically saying that if one player goes above and beyond on optimization and leaves his companions in the dust it will not be fun for his companions, and it will soon not be fun for them.

I stick to Eberron when I DM, however one of the other DMs have invested a lot of time and energy into his own setting, and it truly shows.

The campaign that I am DMing has been going on for roughly 1-2 years and the group is level 12. We meet weekly and start around 6 PM, and try to end it before 1 in the morning.

We are a very combat heavy group usually having combat last most of the session, but we all like role play, and we do get a lot more role play in some sessions.